There is a ball grid array SSD (BGASSD) that is provided in one chip as one type of memory system. In the BGASSD, for example, a memory, such as a solid state drive (SSD), and a device controller that controls the memory are provided in one chip.
In this memory system, there is a limit in the number of times data is written to a NAND memory used in the SSD. Therefore, when the memory system operates for a long time, the debugging performance of control firmware (FW) deteriorates. However, it is difficult to monitor the operation of the processor from pins of the memory system. In addition, when a problem occurs, the problem is analyzed on the basis of the content of a register or a static random access memory (SRAM). Therefore, the experience or know-how of an analyzer is required to analyze the problem.
As one of methods for debugging the memory system, there is a method in which a debug support unit of a processor has a command tracing function and a host device acquires trace information through, for example, a dedicated bus.
However, in this method, the cost of debugging is high and it is difficult to obtain trace information after the memory system is shipped. Therefore, it is necessary to develop a memory system which can easily obtain trace information at a low cost.